The present disclosure relates to the field of power supplies for information handling systems, and more particularly to controlling a direct current to direct current (DC-DC) converter used in power supplies.
As the value and use of information continues to increase, individuals and businesses seek additional ways to acquire, process and store information. One option available to users is information handling systems. An information handling system (‘IHS’) generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, entertainment, and/or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
Typically, IHS's are powered by a power supply system, which include an alternating current (AC) to direct current (DC) adaptor. The AC/DC adaptor receives an AC input and generates a DC output. The DC output is used to provide power to the IHS components such as a processor, memory, and rechargeable batteries. Since each of the system components may have unique voltage and/or power requirements, a conversion of the DC output may be required. Thus, the power supply system may also include a DC-DC converter for converting the DC output voltage level to multiple predefined lower DC voltage levels typically required by various components and/or sub-systems, including the processor.
Power consumed by loads such as processors is increasing from one technology generation to the next. The supply voltage required by the processors is also decreasing and is anticipated to fall below 1 Volt. The combination of lower voltages and higher currents make voltage regulation of the DC-DC converter a more challenging task. A typical approach for reducing transient voltage of the DC-DC converter includes increasing output capacitance and/or increasing the bandwidth of the DC-DC converter. A common method to increase the bandwidth of the DC-DC converter is use of hysteretic control (may also be referred to as on/off, bang-bang, and/or ripple control).
Thus, hysteretic control is a well known non-linear control technique that may increase bandwidth but at a reduced DC output voltage accuracy. A DC error is typically introduced by a delay in turning off and/or turning on of the converter switches. Delays may include propagation delays in the controller design, turn-on and/or turn-off delays in the switches, and designed dead-time control to prevent shoot through. The rate of increase of the regulated output voltage is generally not the same as the rate at which it decreases. This mismatch in “slopes” increases the average value of the regulated output voltage, thereby producing the DC error. Additionally, the DC error introduced by using hysteretic control may be substantial for lower voltage and higher current applications, thereby resulting in inaccurate DC output voltage.
Therefore, a need exists for an improved system to provide power to the IHS. More specifically, a need exists to develop tools and techniques for controlling voltage and/or current output of a DC-DC converter having reduced DC error. Accordingly, it would be desirable to provide for improved control of a DC-DC converter providing power to an IHS, absent the disadvantages found in the prior methods discussed above.